Janssen (lunar crater)
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| Crater characteristics | |
|---|---|
| Coordinates | 44.9° S, 41.5° E |
| Diameter | 190 km |
| Depth | 2.9 km |
| Colongitude | 320° at sunrise |
| Eponym | Pierre J. C. Janssen |
Janssen is an ancient impact crater located in the highland region near the southeastern lunar limb. The entire structure has been heavily worn and is marked by many lesser crater impacts. The outer wall is breached in multiple locations, but the outline of the crater rim can still be observed. The wall forms a distinctive hexagonal shape upon the rugged lunar surface, with a slight curvature at the vertices.
The prominent Fabricius crater lies entirely within the outer wall, in the northeast quadrant of the floor. A number of other lesser, but still notable craters mark the crater floor. Connected to the northeast rim is the Metius crater, and to the north is the heavily worn Brenner crater. Southeast of Jannssen are the co-joined Steinheil and Watt craters. Astride the southwest wall is the smaller Lockyer crater. Further to the east, although appearing nearby due to elongation, is the huge Vallis Rheita.
In the south two-thirds of the Janssen crater can be discerned the remains of a large, concentric crater, the wall of which is overlaid by Fabricus. The floor of this inner depression contains a rille system named the Rimae Janssen. The rille curves from the rim of Fabricius crater to the southeast of the Janssen outer wall, extending for a distance of up to 140 kilometers.
[edit] Satellite craters
By convention these features are identified on lunar maps by placing the letter on the side of the crater mid-point that is closest to Janssen crater.
| Janssen | Latitude | Longitude | Diameter |
|---|---|---|---|
| B | 43.2° S | 34.4° E | 22 km |
| C | 42.8° S | 34.9° E | 7 km |
| D | 48.5° S | 41.1° E | 29 km |
| E | 48.8° S | 39.9° E | 25 km |
| F | 49.7° S | 41.9° E | 36 km |
| H | 45.3° S | 41.7° E | 11 km |
| J | 43.4° S | 36.6° E | 30 km |
| K | 46.1° S | 42.3° E | 16 km |
| L | 45.9° S | 43.4° E | 12 km |
| M | 41.8° S | 35.4° E | 16 km |
| N | 41.4° S | 32.2° E | 5 km |
| P | 45.3° S | 39.7° E | 5 km |
| Q | 46.2° S | 39.4° E | 5 km |
| R | 48.1° S | 38.7° E | 17 km |
| S | 50.4° S | 41.9° E | 8 km |
| T | 48.8° S | 42.2° E | 31 km |
| X | 42.9° S | 33.3° E | 24 km |
[edit] References
- See the reference table for the general listing of literature and web sites that were used in the compilation of this page.
